Dont think about it, just buy the game. Its perfect and charges you how much only you want. Point is in DLCs. They are super cheap (in sales) and most of them (every weapon one) are really worth it. So, you buy game for bucks, then few dlc for one buck, you are at 20, normal store price :/ Anyway, buy it, buy dlcs, dont overthink.

Do you have GF? No more!
Do you have spare time? No more!
Do you have any money? No more!
Do you have family, friends, school or work? No more!
With TEAM FORTRESS 2 your dreams of becoming unsocial nerd will finally come true!
And does it cost 50$? no!
20$? NO!
It is for free, just with a little catch..
Hats. Its hats my friends, they dont help you in any way, apart from your majestic feeling of being someone better.
So, you have game for free, but just because you can, you will inevitably spend few tens or hundreds of $ on just cosmetic items THAT DONT HELP IN ANY SANE WAY! ...
I may be addicted, send help..
...
PLEASE.