Let me start by saying, I've been in a place where I really wanted to move to "the next level" and couldn't justify the expense of doing it, so I get it. And there are definitely people who make
award winning beer using methods that make yours sound like the Miller-Coors brewery. That said,
I cannot brew good beer doing what you suggest.
I've done the two pot method, and I just couldn't ever get it to work right. One pot would boil over and, just when I thought I had it under control, the other one would boil over. Then, once I got that one under control, I'd realize that its boil over had put out the flame on the first pot, and that one had
stopped boiling. By the time I was done, the stove was always a mess, the wort was usually caramelized to hell, and I was pissed.
In addition to the frustration involved, remember that using two pots of unequal size means that your hops will be utilized differently in each pot, making it difficult to anticipate how hoppy or aromatic your beer will turn out. And, for the same reason, you won't be able to follow recipes.
Finally, cooling your wort efficiently will be tough unless you buy two wort chillers (which will be expensive and, if they're sized to fit your small pots, won't be useful for when you do upgrade.) Sure, with two pots you can throw them both in the sink with ice, but that's a very slow method of cooling a 4.5 gallon volume of liquid. As a result, you'll be at a greater risk of developing DMS and DMS precursors. The risk will be more significant if your sink is not large enough to fit both pots at once. And the final nail in the cooling coffin is that chilling beer in your sink (or bathtub for that matter) is an invitation for infection.
Here's a link to a $44 dollar turkeyburner and 30Qt. pot. That's a little more than half what I spend to brew my Double IPA, or approximately the cost of brewing a standard all-grain pale ale. Consider skipping your next brewday and spending the money of that pot and burner instead. If you decide you want to forge ahead with the two unequal pot method, that's fine too, but know the option is out there.