| Oct 5, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Auction | $10.80 |
| Oct 1, 26 | CGC 7.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 7.5 NRMT+ · Fanatics | Buy It Now | $10.00 |
| Sep 28, 26 | PSA 10 | 1999 Pokemon Base Set Professor Oak #88 PSA 10 GEM MINT · Fanatics | Auction | $144.00 |
| Sep 26, 26 | CGC 8 | 1999 Pokemon Base Set Professor Oak #88 CGC 8 NM-MT · Fanatics | Buy It Now | $15.00 |
| Sep 3, 26 | CGC 8 | 1999 Pokemon Base Set Professor Oak #88 CGC 8 NM-MT · Fanatics | Buy It Now | $10.00 |
| Sep 1, 26 | PSA 9 | 1999 Pokemon Base Set Professor Oak #88 PSA 9 MINT · Fanatics | Buy It Now | $60.00 |
| Sep 1, 26 | PSA 9 | 1999 Pokemon Base Set Professor Oak #88 PSA 9 MINT · Fanatics | Buy It Now | $60.00 |
| Aug 31, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Auction | $10.80 |
| Aug 31, 26 | CGC 7.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 7.5 NRMT+ · Fanatics | Auction | $6.00 |
| Aug 31, 26 | CGC 8 | 1999 Pokemon Base Set Professor Oak #88 CGC 8 NM-MT · Fanatics | Auction | $6.00 |
| Aug 12, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Buy It Now | $17.00 |
| Aug 11, 26 | CGC 6.5 | Professor Oak 088/102 Base Set Unlimited CGC 6.5 · eBay | Auction | $0.99 |
| Aug 3, 26 | PSA 10 | 1999-2000 Pokemon Base Set Professor Oak #88 PSA 10 GEM MINT · Fanatics | Auction | $93.60 |
| Jul 23, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Buy It Now | $17.00 |
| Jul 19, 26 | PSA 7 | Base Set #088/102 Professor Oak PSA 7 · eBay | Auction | $32.99 |
| Jul 5, 26 | SGC 10 | Professor Oak 088/102 Base Set Regular SGC 10 GEM MINT · eBay | Auction | $3.25 |
| Jun 18, 26 | PSA 9 | Professor Oak 088/102 Base Set Regular PSA 9 · eBay | Auction | $36.00 |
| Jun 15, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Auction | $9.60 |
| Jun 3, 26 | PSA 9 | 1999 Pokemon Base Set Professor Oak #88 PSA 9 MINT · Fanatics | Buy It Now | $47.00 |
| May 28, 26 | PSA 10 | 1999-2000 Pokemon Base Set Professor Oak #88 PSA 10 GEM MINT · Fanatics | Buy It Now | $147.00 |
| May 24, 26 | Ungraded | Professor Oak 088/102 Base Set Regular CGC Graded 8 · eBay | Auction | $5.00 |
| May 15, 26 | Ungraded | Professor Oak 088/102 Base Set Regular CGC Graded 8 · eBay | Auction | $5.00 |
| May 13, 26 | cgc9_6 | 1999 Pokemon Base Set Professor Oak #88 CGC 9.5 MINT+ · Fanatics | Buy It Now | $25.00 |
| May 2, 26 | CGC 6.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 6.5 EXMT+ · Fanatics | Buy It Now | $7.00 |
| May 1, 26 | CGC 6.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 6.5 EXMT+ · Fanatics | Buy It Now | $7.00 |
| Apr 6, 26 | CGC 6.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 6.5 EXMT+ · Fanatics | Auction | $6.00 |
| Apr 6, 26 | CGC 6.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 6.5 EXMT+ · Fanatics | Auction | $6.00 |
| Mar 24, 26 | PSA 10 | PSA 10 Professor Oak 088/102 Base Set Unlimited · eBay | Auction | $119.99 |
| Mar 9, 26 | CGC 9.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 9.5 MINT+ · Fanatics | Auction | $8.40 |
| Mar 5, 26 | CGC 6.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 6.5 EXMT+ · Fanatics | Buy It Now | $37.00 |
| Feb 16, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Auction | $9.60 |
| Feb 9, 26 | CGC 10 | 1999 Pokemon Base Set Professor Oak #88 CGC 10 GEM MINT · Fanatics | Auction | $26.40 |
| Feb 9, 26 | PSA 10 | 1999 Pokemon Base Set Professor Oak #88 PSA 10 GEM MINT · Fanatics | Auction | $72.00 |
| Feb 2, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Auction | $12.00 |
| Jan 29, 26 | PSA 10 | PSA 10 Professor Oak 088/102 Base Set Unlimited · eBay | Auction | $119.99 |
| Jan 18, 26 | PSA 9 | Unlimited Professor Oak 088/102 Base Set Regular PSA 9 · eBay | Auction | $55.00 |
| Jan 5, 26 | CGC 7 | 1999 Pokemon Base Set Professor Oak #88 CGC 7 NRMT · Fanatics | Buy It Now | $7.00 |
| Jan 5, 26 | CGC 9 | 1999 Pokemon Base Set Professor Oak #88 CGC 9 MINT · Fanatics | Auction | $8.40 |
| Jan 5, 26 | CGC 5 | 1999 Pokemon Base Set Professor Oak #88 CGC 5 EX · Fanatics | Auction | $6.00 |
| Jan 5, 26 | CGC 5.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 5.5 EX+ · Fanatics | Auction | $6.00 |
| Dec 29, 25 | CGC 4.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 4.5 VGEX+ · Fanatics | Auction | $6.00 |
| Dec 22, 25 | CGC 7 | 1999 Pokemon Base Set Professor Oak #88 CGC 7 NRMT · Fanatics | Auction | $6.00 |
| Dec 15, 25 | CGC 8.5 | 1999 Pokemon Base Set Professor Oak #88 CGC 8.5 NM-MT+ · Fanatics | Auction | $12.00 |
| Dec 15, 25 | PSA 10 | 1999-2000 Pokemon Base Set Professor Oak #88 PSA 10 GEM MINT · Fanatics | Auction | $62.40 |
| Dec 8, 25 | CGC 10 | 1999 Pokemon Base Set Professor Oak #88 CGC 10 GEM MINT · Fanatics | Auction | $15.60 |
| Dec 1, 25 | CGC 10 | 1999 Pokemon Base Set Professor Oak #88 CGC 10 GEM MINT · Fanatics | Auction | $18.00 |
| Dec 1, 25 | PSA 9 | 1999 Pokemon Base Set Professor Oak #88 PSA 9 MINT · Fanatics | Auction | $25.20 |
| Nov 24, 25 | CGC 10 | 2000 Pokemon Base Set Professor Oak #88 CGC 10 GEM MINT · Fanatics | Auction | $13.20 |
| Nov 4, 25 | PSA 10 | Sold Nov 4, 2025PSA 10 GEM MINT Professor Oak 088/102 Base Set Rare 1999 Pokemon WOTCOpens in a new window or tab · eBay | Buy It Now | $70.00 |
| Sep 14, 25 | PSA 9 | Sold Sep 14, 2025Professor Oak 088/102 Base Set PSA 9Opens in a new window or tab · eBay | Buy It Now · Best offer | $19.99 |
