My steering box is also leaking like a sieve and steering is loose. I'm the kind of guy that likes to rebuild everything myself (just check out some of my threads), but even I'm leaning towards a new box on this one. Why? Well, if you just want to fix the leaks, a reseal kit will do that. That's about $120USD, and if you do the labour yourself and just do the seals, sure, that's an option. If your box is clapped out and your steering wheel has massive play in it though, you really should be fixing that. I want to fix that issue. What's involved in that? Well, to fix the play, you actually need to replace the cross shaft, and the gears inside the valve assembly, which aren't sold separately so you need the whole assembly.
For my rig, a HZJ80, here are the bare essential prices I'd need to pay to fix my steering wheel slop today (Partsouq prices):
274.69USD - SHAFT, CROSS
740.33USD - VALVE ASSY, W/BALL NUT
116.68USD - Gasket kit
And since I'm replacing the cross shaft, there's really zero reason not to do the sector shaft upgrade I'd get with the new box, so let's throw in a new pitman arm:
92.95USD - ARM, PITMAN
That's 1224.65USD, and I haven't replaced the bearings, springs, nuts, etc. I still need to clean up and paint the box in some decent enamel paint, do all the labour for the rebuild, and either source a new box to do the rebuild on, or have my rig off the road for a bit while I do all this work.
And what's the current price of a brand new box, with the upgraded sector shaft from the factory? 1965.78USD. Plug and play, everything brand new, AND I have an old box I get to keep and put on my shelf, and can still mess around with rebuilding later or use as an emergency spare. With a minimal DIY rebuilding being 2/3 the cost of a new box, it just isn't worth doing a rebuild yourself, cost-wise.
Now, as for rebuilt boxes from various places, if they're less than 1224.65USD, how do you think they're doing that? They can't get a cross shaft and new valve assembly from Toyota for cheaper than you can, so do you think that's included? There isn't a shop out there replacing those critical worn parts with new genuine parts, because if they did, it'd cost significantly more than the cost of a new Toyota box once you factored in the labour and markup to make it worth their while.