If you see a ship/Sparrow you think looks awesome, then go for it. You have to look at them a lot so why not get a vehicle that looks nice?

The very first thing I bought, when I could afford it, was a new ship... They don't do anything, so many people say they are a waste of glimmer. I, however, couldn't stand having the same old ship as everyone else, and wanted to be able to stand out among a group of ships in orbit, or traveling to a destination. As far as sparrows go: for the most part it's the same deal... I still have the gamestop preorder red sparrow because it's the middle tier model, and I've yet to find one I like the looks of more. I feel like sparrows don't get noticed as much as ships, so I'm refraining on buying a new one until I can get a 3rd tier one (with strafe boost) unless I fine one that looks super awesome (doubtful)

I enjoy looking at my shiny new ships in motion on the loading screens. (Even got a rare one randomly from a bounty) I bought a couple sparrows as well (had extra money) just for the different colors. It's for your enjoyment

I'd likely spend the glimmer on a faction emblem and raise my cryptarch by buying engrams...never played beta tho so only a few days in here, others may have better ideas. I wasted 5k on a ship and sparrow then got upgraded ones free in the quest chain