If i were looking for a base used 6 speed rx8 maybe 6-7 months down the line, what would should I be expecting to pay?

about 23-26k

Used? I reckon around $22K.

25k, since when i bought mine there were 8s that people returned after the buy back option happened and they were going for 24 to 25k

That is a difficult question. We can't really know because many factors will effect price. In 6 months, the 2005 models will be out, and there will be more people willing to sell their 2004. Especially if the 2005 has engine upgrades.

Anyway, Edmunds shows dealer invoice of $24,500 for a base 6MT. Add in destination and you have an even 25,000 price tag (new). So used in 6 months, I don't see you paying more than $22k-23k range max. Maybe less.