Unfortunately, yes. I think most folks have found that "rolling your own" is considerably more expensive than buying one already done. Especially when you are going after LR tanks and STOL kits that are typically already installed in that price range.
There is a recent post by a member going through the conversion. Haven't read anything on him lately, but he could probably give us some insight.
I think there was even a post that outlined the $$$$ by line item. Seems like (very bad memory hear) like it approached $55-60,000 when you were all done.