The cost of getting those into space is a relatively small part of the overall cost. The amount of cost benefit one of these telescopes would see just to the cost reductions gained specifically because of Starlink are insignificant.
> The cost of getting those into space is a relatively small part of the overall cost.
Well, technically, I suppose you could argue that the direct launch costs are small. However, most of the cost of the telescope itself are driven by the high launch costs.
That's the classic problem for satellites: Launch is expensive, so you can't afford to fail. So you have to use mil-spec everything. Every screw has to come with a piece of paper attesting to the provenance of the chromium used to make the stainless steel. Every system has to be built and tested and have triple redundancy. You have to use teflon-insulated wires, because god forbid anything outgases while on orbit. You have to over-build everything, and test all the vibration modes on those giant vibration tables NASA owns. So now "the satellite is expensive". Oh, and since the satellite is expensive, the launcher can't afford to fail and costs just spiral out of control.
But look what happens when you have cheap launches: You don't care if the satellite has a 1% chance of failing. If it does, learn from your mistake, make that one thing better and launch again. Now that you only need two nines instead of five, all of your costs go down. You can use regular-grade chips, and hardware store screws. Instantly the price of everything drops by several orders of magnitude.
The cost of launch is small-ish compared to the total program cost, but the limitations on launch condition the engineering requirements in ways that inflate the engineering costs. JWST had to be built as an insane on-orbit autonomous origami project because its mirror couldn't fit in a fairing unfolded. Repeat for ten thousand other decisions that are made in order to optimize weight or volume.
If you can launch a hundred tons to orbit for $5M, you can just make a huge dumb cheap telescope and throw a dozen of them up there. Quantity covers a multitude of sins.
