I was an ID grad. When I was in school I think probably 60% of students went into some type of technical sales and mostly worked for wholesale distributors in the electrical, hydraulic, PVF, plumbing, or building material sectors. Others, like myself, went more into procurement/materials management. I've had titles ranging from category manager, materials lead, procurement specialist, etc. I've also known some guys who have taken quality management roles for manufacturers.
Salaries are going to vary quite a bit in early career depending on what kind of path you take. A first year salesman may only clear $50-$60k while a first year procurement analyst at a large O&G company may draw closer to $75k or more. Many jobs are going to normalize in the low to mid six figure range as you get closer to 10 years experience. Some sales roles will shoot up much quicker depending on the individual or company.
Most of your ID grads are probably tied in with O&G or commercial construction. However, I've taken interviews with the likes of Google, Apple, and SpaceX. A lot of high tech companies have recruited O&G pretty hard in the last few years and there are some ID grads among those.
I've heard good things about the masters program. Most who already have a bachelors in ID will not pursue the masters since it has most of the same coursework. I do know there are a good number of business and construction management degrees who decide to add on a masters in ID. This is especially true if they're already working in the distribution business and looking at running a division or taking on a sales leadership role.