My rear has a 2.73 Posi in it. However, now its a one legger.

I"m sure the clutches on the posi unit are bad. I cant afford to go all out and build a crazy rear, but i would like to at least get them both spinning again. So is it worth rebuilding the posi unit and putting 3.xx while im at it? Or should i just buy a complete stock posi rear from somewhere for like 300 bucks? If i were to go the rebuild route how much harder is it to rebuild than a non posi unit??