td04 is a good turbo, but the 19t upgrade is expensive for what it is, with very minimal gains.
you're looking at the cost of the turbo, +$325 for the upgrade, + any extras you want, such as porting, ceramics, or any repairs blouch needs to make to the turbo you send them + shipping, etc. . ..
for that money, you could get a good condition 39, 23, 24, or 16g.