I've recently played with the Korg Monologue, it's a solid machine, analog synthesizer and step sequencer, enough standard ports to extend it eventually - a criticism to the device mentioned in the OP is that it's pretty nonstandard in a bigger workflow. It's < $300, still not cheap but a pretty good package overall.

A lower price is the Korg Volca, at $100 - $150 per unit. They're less versatile though and you'll probably end up having to buy / link up multiple.

Even lower and you're looking at stuff like the Teenage Engineering Pocket Operator series, single card devices in the $70 range. There's a wide range of variations, each of which (correct me if I'm wrong) has 16 instruments and a programmable step sequencer, 16 patterns preloaded. The preloaded patterns have only 16 steps, but you can program it to have more than that and switch between patterns every 16 beats. You can link up multiple together as well, they can synchronize with one another (iirc you have to hook up your phone as the first step which generates a synchronization signal).