Everyone has different ideas about what's best. I for one would advocate buying a putter within your price range that has the best putting stats (precision, balance, forgiveness, etc). If you don't learn how to read the greens properly no putter is going to work for you ^^.
Once you learn this skill then better stats (on the putter) translates to balls hit on true lines which will result in more putts dropping. So learn how to read the breaks and then buy the best putter you can afford.
I could care less about putter scale. Imo this has absoultely no relevance. You adapt quick enough and once again, the more precision, balance, and forgiveness a putter has the more putts you'll sink. I've gone through 3 different putting scales with my putting improving with every change (after slight growing pain).
Anyways, don't let your "comfort" zone with a putter scale hold you back from improving.
Cheers. Sean.