First impression is that you've got kind of a shitty attitude towards people who offer help. If you don't like the advice you receive (based only off the info you presented), don't be a brat.
How much weight do you currently have? What are your current PRs (even if they're for reps and not 1RM)? What does your current weekly plan look like - days, exercises, sets, and reps?
As was said, the best case scenario would be to pick up some more weights. If you can't save a few bucks a week for next few months, that's fine. Budgets are a personal decision. But, at the end of the day, if strength is your number one priority like you said it is, everyone's right when they said you need to invest in more plates some time down the road.
Keep an eye on Craigslist to pick up weights when they pop up. Hell, I just checked online and Dick's Sporting Goods has a 300-pound Olympic set, barbell included, for $200. How reasonable it is for you to drop $200 on bunch of decent weights that'll basically last your lifetime is your decision.
Mechanical advantage work can certainly be a great tool to get the most out of limited weights, but it does generally tend to be used more for hypertrophy. And also, it still requires you to bench, squat, and deadlift to fatigue (not failure). For example:
I second the suggestion for "grease the groove" work like Dan John has laid out here:
In that plan, the weights are never supposed to feel heavy, so it's perfectly acceptable, even intentional, to use a lighter to moderate load.
Another option to consider, since I see you're a pretty large kid from your stats (5'10", 235, "roughly 15%" bodyfat [um, okay]), is heavy complexes. Kinda-sorta related to mechanical advantage work in that you're working similar movement patterns consecutively. But you do them in a row, with the exact same weight, without resting between.
So you could do something like: high pull 2 reps, Romanian deadlift 2 reps, deadlift 2 reps. Or even as basic as: Deep pause squat 3 reps, parallel squat 2 reps, quarter squat 2 reps. Dan John has also written a ton about complexes and their multiple uses.