Where's that guess coming from? The scope is $18, the optional probe from elecrow is $5 extra. You most definitely have either an android phone or a laptop/PC with a browser from the last ten years already. As such the cost is pretty minimal. Say you bought a set of these kind of test probes with hooks at the front. A set would maybe cost you $10. Now you can use all your 9 channels. I don't understand your price calculations.

Every scope out there has an upper limit in terms of speed. If you have no use for it, don't buy it. This oscilloscope is first and foremost a learning resource.