Sure. that's kinda true (converters easily sell for 80K now, so there's 800K back in your pocket...
But more importantly, it would be silly to only roll for LotG...
buy cheap yellow recipes that don't require rare salvage...buy at a level like 31, 32, 33, or something so that you don't have 4 different types of sets for that category
buy converters (for Pete's sake, don't pay 100K, it would make Pete sad)
You Goal now is to convert to any rare set that is more valuable that what you paid - i.e. must sell for at least $1.5 Million or more
If you convert to an especially good rare set, like Healing, Resist Damage, Defense, then you are going to go the extra mile to get a big seller, but 80% of what I sell only sells for $1.5 to 2.5M, but it only takes 2-5 converters to get there...If I during those few conversions I get a really good one, then I'll spend the extra 3-15 converters to get something really good...
EDIT: I would be extremely remiss, if I didn't include this guide! If it's helpful, please give Shinobu a big like!