How do you deal with the higher cost and lower availability of medium format film and cameras?

While it's true you can get excellent image quality from a 35mm scanned into digital, if you're looking to push or pull the development of a specific image you would be incredibly hard pressed to do so with 35mm, whereas a 4"x5" is a single shot, and can more easily be marked to push or pull development so you can expand or contract your exposure range during development of the film and 35mm doesn't allow for that.

True, if you want a quick and mobile system 35mm is ideal. It's hard to shoot dance photography on 4x5 film, with medium format you shoot less images, but with greater control over exposure in finite areas.

The truth here is 100%. A caveat is it's hard to make palladium or platinum prints out of 35mm, unless you digitally convert and print a reversed inverse on velum to make a contact print with palladium or platinum. Salt printing requires similar treatments to receive the same result.

Developing and dSLR scanning at home has helped me cut costs a lot, film labs are few and far between these days and the price for development and scanning reflects that. There is the initial costs of chemicals and equipment, but if you find yourself using them for more than 15-20 rolls or so you’re saving more money in the long run. It can also be a bit time consuming, but it really gives you the control of every single process of development. Personally I think the benefits are well worth the time and effort.

Agreed, completely. A caveat is we're more willing to take a bad shot when we have more ability to take a bad shot, so the ratio of great images taken goes down substantially. Digital has pushed this reality even further. Don't forget though that there are digital medium format cameras available, just the cost is significantly more expensive than a film camera of any sort, or a full frame 35mm equivalent digital system.

While 35mm here has been posed as an option providing ‘freedom and flexibility’ there is something to be said for distinguishing yourself as an expert by perfecting your craft through medium format film. As was said earlier, it remains tried and tested for quality and results, and if you know where to look, it’s not as hard to source as you might think. When you become an expert with the medium, you can charge clients accordingly to the quality you will be able to deliver.

My area of photography has been Advertising and Entertainment in these areas of business the medium format has dominated the field. Many times the choice is determined by the needs of the client. Which for me the choice is made in advance. In terms of film my team and I plan for the inability to find film or other resources in the course of our travels. This advanced planning insures a successful project.