Okay, I've written this umpteen times in response to other posts, so why not make it a thread that at least I can point to in the future. Here goes:
IMO, and many others, Rocket Boost is the single best quality of life item you can buy in the game from the Cartel Market. Get it. You can thank me later
What is Rocket Boost?
It is an ability that lets you travel at +110% (that means 2.1x) normal speed for 12 seconds. Like a mount @ 'Speeder piloting rank 3'. But it can be used in places where a mount doesn't work. Like buildings and caves. A GREAT time saver!
Note: it is legacy-based, so one unlock applies to all characters on that legacy (server).
What's the catch?
It has a 2 minute cooldown. And it costs a fair # of credits or Cartel Coins (CC).
But it has 2 upgrades, that reduce the cooldown to 30 seconds.
What you have to do:
Purchase with credits or CC. Credits are Legacy level locked unfortunately, so if you are starting out, CC are the best/only way.
Cost:
Rocket Boost is 2M credits, with Legacy >=8 required, or 400CC (no Legacy restriction),
BUT, you should instead purchase the 'Going Places Bundle' on the cartel market (unlocks category) for 375CC which comes with other stuff you can use or vendor!
The two upgrades are purchased from the Legacy panel > Global Unlocks > Other. Right hand side
Improved Rocket Boost I (reduces CD 30sec): 1M credits, Legacy >= 10. Or 120CC,
Improved Rocket Boost II (reduces CD 60sec): 1.5M credits, Legacy >= 12. Or 120CC,
So, total is 375 + 120 + 120 = 615 CC.
Save your first 500 CC sub perk, make a security key which gives another 100 CC. And run one character through the starter planet (20 CC), and you can purchase the whole set.
IMHO, it is a lot better than wasting the 500 CC on a lightsaber shell (or anything else on the CM).
Hope this helps.

Aka DocDAM, aka DocDIM
My Refer a Friend link here (DocDAM). [Rules and Rewards]