Lipo and BBL are done together, you need Lipo in order to obtain the fat you need to transfer to buttocks. It isn't considered too much to have both procedure at the same time. You can have Lipo without BBL if you think you don't need extra size or projection on the buttocks, but, like I said, you can do both at once, and it will not be 'too much', and it will be more affordable, depending on what Doctor you choose. I hope this answer was helpful.
It is necessary that if you want fat transfer a liposuction has to be performed also. Usually the fat transfer raises up a little the price than when only getting liposuction .it is perfectly safe to have them done together , since there is no transfer without lipo.Best wishes