boooosted

My buddy wants to sell me his 8.8 rear end, Its in great condition and it has a 3.55 gear. he's selling it for $150. I have a stock gear now and was wondering if this would be a good buy and how much would I benefit with the 3.55. I was wanting to go 3.73 or 4.10 but It would cost me more than 150 for just the gear and then I would have to have it installed thats probably another 200-300 bucks. Well let me know what I should do. thanks