Here are the things I see, which hopefully will help you make an informed decision.
The cab was painted red, when it was originally a blue machine. The front panel was hacked to put the on/off switch in a "more accessible" location.
Being a D2K kit, scores on this hardware will be acceptable for DKF submission. Might not be acceptable for TG submission. (Someone correct me if I'm wrong.)
It also appears to have original buttons, which is a plus.
The seller notes it is a TKG3 cabinet, although painted incorrectly red. The order of collect-ability, in most collector's minds, is: TKG2 is most collectible, TKG3 is next most collectible, TKG4 is least collectible. But, even TKG4's are desirable to have in most collector's collections.
The original power supply was replaced with a switching power supply. The switcher is considered better for reliability and longevity, but just something to note, if you ever want to return it to original. Also worth noting - a TKG3 would have come with a 4-board PCB originally. This one has a 2-board set.
Other things that I see, which tell me it could be a good investment - the locks appear to be original, the rear door appears to be complete, the t-molding looks to be correct (flat, not convex...probably replaced when it was painted, but at least care was taken to replace it with the right stuff).
One other thing that I see that could be considered flaw - the wheels on the bottom were added, and will make the cabinet sit higher than it natively would.
Just some things to consider. As with all things, if you are purchasing more for personal use than as an investment or to try to flip, then if the price paid is within your budget, it is a good purchase.
