That is certainly an option.
Set back and rechamber, looks to be about $375 done by LRI, if you want to get it cut and threaded, add $125 from LRI. Lets ignore the $80 in shipping, say you live local, and call it $500.
You can sell the barrel for $150-200. You can pick up a PVA Osprey barrel for $660 if you wait for a sale. That puts you at $510. The PVA barrel will likely be better than the set back and rechambered Tikka barrel, and it will be easier to get fixed if it does not shoot well.
If you have to pay someone to install the prefit, it will add a touch to the cost.
You can get a Preferred Barrel blanks prefit that is threaded for $550 and an X-caliber is about the same price.
Plus, the 1-8 twist is a touch slow for 109 gr ELDMs or 110 gr A-tips, so for roughly the same price, you can get a faster twist that is more appropriate for the high BC bullets.
My personal choice, having just acquired a 1-8 243 Tikka is that I will shoot the barrel out, the rebarrel. It will cost me the addition of a set of go/no-go gauges and the $40 I spent on the RCBS 243 dies. Cut/thread including shipping, adapter, and thread protector cost $230, so comes out cheaper than immediately replacing with a 6 creedmoor barrel (of course, if I had used the action from my 308 Tikka, a prefit would have been cheaper, but the deal on the new Tikka was too good to pass up).