Bright dust shouldn’t be a currency to buy tributes in the tribute hall. It’s an in game currency which can be bought with real money, which could encourage spending of real money to complete the tribute hall. This could be an oversight on Bungie’s behalf however it shouldn’t be used here, it’s a vanity item/ eververse currency. Not to mention it’s quite difficult to farm in large quantities required to buy the tributes.
I dismantled all the ships and sparrows and any shaders I had from Eververse packages and did the five that you bought with dust with ease. Anyone who would pay real money for engrams which would give probably a worse return than that doesn't know what the hell they're doing.