SpaceX doesn't do self-funded science projects. I'm not really sure where you get that impression. More to the point though, Venus is extremely inhospitable. O

SpaceX doesn't do self-funded science projects. I'm not really sure where you get that impression. More to the point though, Venus is extremely inhospitable. On the surface the temperature is hundreds of degrees and the atmospheric pressure is equivalent to about 900m below the ocean on Earth. The solar flux at the surface is also too low for a lander to use solar panels. So even if NASA or whomever wanted to spam Venus with landers, there's no real way to make them low cost as their main mission lifespan would be measured in hours at best. Because of the surface pressure a lander would need to carry robust shielding for instruments and electronics. Because of the surface temperature the lander components will eventually overheat. Thicker shielding will delay the overheating but that eats into the lander mass budget for science payload. Photovoltaics are out for power so the only options are chemical batteries or an RTG. An RTG isn't a realistic option since the environmental temperature is too high for it to cool and keep from melting. Some sort of buoyant probe design isn't all that practical either. While upper parts of Venus' atmosphere are more hospitable than the surface, there's clouds of sulphuric acid and incredible winds to deal with. The density of the atmosphere is such that there's only a few kilometers of visibility so probe's floating in the lower density upper atmosphere wouldn't have any better ability to image the surface than orbiters. So you're looking at Venus landers that look more like bathyspheres (no rovers) powered by chemical batteries. You're dropping them into an extremely high pressure furnace where they have a life expectancy of minutes to hours. I don't know how you'd expect to do such missions at a discount. Even if you somehow got the mission cost to a low tens on millions of dollars you're looking at ones of megabytes of scientific data for that price. Space is hard and some parts of space are super hard. Funding is finite so getting the best scientific ROI is important. Littering Venus with steel spheres and parachutes for a few megabytes of data doesn't have nearly the return of a rover on Mars.