Advice on Buying ~ 1999 Samsung SE 280 LC < Good, Fair, or ____, are they OK ?

I'm Looking at a -- 1999, Samsung SE 280 LC, has 3,9XX hours, it runs & moves and in good (hoe pic's. shows low hr's. wear) condition.. except one item; It's reported to need a -- Control Valve Replacement, it's Bad. What is the ball park guess for cost of a -- Samsung Control Valve $ _____ . __ __ ? This a Bid Type Auction... any thought's on what this machine would be worth. I did some checking on Mach. Trader, the SE 280's were going for -- $ 14,000 K for a parts machine, $ 34K for a good shape 1996 SE 280. I was thinking around -- 14 K to 18 K as my top bid for a hoe with a broken control valve, & ___ ? it's a-pig-in-a-poke deal and could be a costly problem child. It's a 30 ton hoe and not cheap to move but another reason that some people won't bid on this size hoe. I listed the 2nd (below) machine I may bid (96 Hyundai 280) on; Please, share your thought's on this one as well. 1996 Hyundai 280 LC, has 75XX hours, Cummins 8.3 Engine. It's reported to have -- Wear in Pins & Bushings in Boom, UC Wear, Inst. Cluster is InOp. . It has a 8.3 Cummins engine, were they good engines ? I was a road man for Cummins in PGH and later... worked the coal fields, I retired 15 years ago. I don't know the Cummins 8.3 engines, did they burn a lot of fuel ? I still have my tools, road truck with crane and set up to do all levels of repair on hvy. equip. but not what I want to do everyday in retired life @ 65 YO. I need a bigger 20 Ton + for digging a big pond and putting in a -- 2 mile mtn. road in PA. The digging is in real tuff in red shale, sparks come off new teeth (it's like concrete). I'm in the process of putting together a Ripper Kit together to add on the back side of the bucket of the hoe I buy, check the Hensley design, see link below. http://www.hensleyind.com/parts_boo...k_Tools/Box_Ripper_Systems_for_Excavators.pdf Thank You, Avery