Premium time, or hold off until after the patch next week and review the Cataphract first
How long have you been dropping into combat?
Are you simply looking for an engine upgrade?
What is your goal concerning your Yen-lo?
If you are concentrating on the Centurions, I would look at the other variants first, as that will allow you to equip one out, get the MXP, purchase all of the Pilot Lab/Basic items to unlock the Master tier then move on.
But what many have done, especially the founders, is purchase the Atlas K for tis 300XL engine, sell back the chassis only while keeping everything else. For a few they purchased mechs w/XL engines and sold back the chassis again. That provided them with the high priced engines and other parts while filling out their bank with C-Bills with the conversion.
Also, even if you do not have the C-Bills to purchase an item, such as an engine, in the mechlab it will list the highest rated engine for that particular variant. On some mechs, the engine list may only go up to 260. That will give you an idea on the what engines can be used in that mech so you do not purchase another mech and find out its engine will not work in the other mech.
Edited by Tarl Cabot, 16 November 2012 - 09:57 AM.