Which items to skimp on for a home gym?

[TempestTenor]

Here are the items I need for a home gym and some approximate prices (after tax and shipping if applicable):
Sumo Rack $400
Weight Tree $45
Adjustable Bench $70 - $130
Stall Mat $33
Plates $.79/lbs - $1.45/lbs
Barbell $90 - $177

I'm having a hell of a time trying to decide which items (particularly plates) would be okay to skimp on. Let's go through them in order:

Sumo Rack: definitely don't want to skimp on a rack. In fact, I only have one choice here which is to buy from New York Barbell. They're the only ones that sell the kind of short rack I need.

Weight Tree: I think I can skimp on this one. There's one for $60 online, but I saw a crappier one for $45 today at Dick's. I'm sure I'd be okay with the cheaper one.

Adjustable Bench: I haven't been able to find any new or used ones at local stores or on craigslist that don't have the attached stands. I would prefer an adjustable bench, but I can settle for a flat bench. I can probably go middle-of-the-road on this one.

Stall mat: Can't get any less expensive than this This is the price from a local Tractor Supply Co. with an online coupon

Plates: I need the most help on this item. I will not be doing Olympic-style lifts for a while and if/when I do, I'd go get some bumper plates. Are high quality plates really all that necessary? How much stress do they really go through from loading and unloading?

Barbell: Probably shouldn't skimp on this one. I've seen a number of barbells of questionable quality for $80 - $90 at Dick's and at a local used sporting goods store (Play It Again Sports). Haven't seen any good ones on Craigslist. I'm probably better off ordering a new one from more reputable sites.

[muddy]

In my opinion, no, you do not need expensive metal plates.

I don't know how similar the market is there to here, but I wouldn't pay any more than $0.50/lb for olympic plates, with a better price being more like $0.40/lb or on rare occasions even cheaper. (The one exception is 100lb plates - these are hard to find, and when sold, people seem to ask more for them, say around $0.70/lb.) If you are patient, you can find them for less when some gym closes or someone is just desperate to unload a lot of them. For metal plates, there isn't much to worry about quality. Things you may want to worry about would be:

- Excessive rust, because if bad enough, it will reduce the weight of the plate. Very minor surface rust can be dealt with if the price is good.
- If you buy some here, some there, the sizes can sometimes be a tiny bit off for some peculiar brands. if you can find someone selling all the weights you need of the same brand, you're probably better off. otherwise, once you buy some 45s, take those 45s with you when you go to look at other 45s so you can make sure they are a fit size-wise.
- Most people prefer round plates and not the 12-sided ones. if you are deadlifting with these (i.e. these plates will start on the bar from the floor), you'll want round ones.

Bumpers are hard to find used in my experience. You'll pay a premium for the narrow bumpers. The cheaper bumpers are considerably wider than a normal 45. While durable and good quality, it means you cannot get more than about 445lbs of bumpers on the bar for e.g. deadlifts. I've personally been happy with the WFW bumpers sold by muscledriver (now discontinued). Muscledriver does a pretty good job rating the bumpers now, too.