Can Mikrotik make something less expensive?

You mean a SFP+ to 10GBASE-T converter?

That would be one, for 40G breakouts, for example. But some people would want optical.

Also a 1000Base-T to SFP extender that allowed to plug in a modem. Some people would need PoE.

"1000Base-T to SFP" sounds like a media converter. The RB260GS(P) almost does that for the same price as a generic converter. Then you have the RBFTC11.

I don't understand the 40G breakout thing.

I don't think it is obvious that you can use a modem in an SFP media converter, that's why I said extender.

There are much cheaper converters than Mikrotik's cheapest switch or outdoor converter.

I haven't seen anybody using an SFP modem under SwOS or the converter.

Price is not everything. Size is also important.

Some people need PoE in. Others need PoE out.

i have seen 40G breakout cables to SFP+ or optical. What happens when you can't connect everything the same way? You need media converters, and 10G is expensive.