There are different types of solar filters.
What features, if any, on the Sun do you want to photograph?
Or do you just want a white circle that has no detail?
For the Sun to have much in the way of scale in the frame you'll need quite a bit of magnification.
The least expensive filters will let you see/photograph sun spots.
You can make a DIY filter for your camera lens using a small sheet of solar filter material like the Baader film or like this: 4"x4" Solar Filter Sheet for Telescopes, Binoculars and Cameras
Or you can use a small telescope with a solar filter on it if you want the sun to have more scale in the image frame.
If you want to see/photograph solar granulation and/or prominences you'll need to use a hydrogen alpha filter.
At the low end small 40 mm, f/10 solar telescopes with an internal non-removable 1.0 angstrom hydrogen-alpha (Ha) bandpass filter start at about $630: Meade Instruments Personal Solar Telescope