Got 03 rev 800 with bike man pipe, can and bikeman team roller clutch kit. 1'5 rip saw track, delete kit, pretty much new everthing, should i buy a new 09 800r or keep this one and turbo it?

A few questions that you need to answer for yourself.

What type of riding do you doo most?????
How many miles a year do you put on?????
What kind of time are you willing to dedicate to the sled in between rides.(maintenance)
How deep are your pockets??????
Not a lot of return on putting 5 to 6 grand into a 6 year old sled.

2 stroke turbo's are a bit on the spendy side and need the attention of a very
experienced tuner.
Have had an 04 Rev with a Straight Line Kit and a 06 wth the BMP kit.
Both were excellet performers.
The 08 XP did not disappoint at all.
Best of luck.

Buy new.