Hi there. I wanted to offer a few personal experiences that I hope might be of use to you.

First of all, I'm just your average DIY'er - but I'm an old man at 57 with a lot of DIY scars to show.

While you surely can buy your cabinets at one of the big box stores as others have commented they will be a) lower quality and b) more expensive than some other options. So let's look at those options:

• Keep your existing cabinets but upgrade the doors. My wife and I did this years ago and were very happy with the result. We had an old Sears Craftsman home on the national registry. The kitchen cabinets were solid but they had very plain doors. We removed the doors, painted the cabinet frames a blue color that my wife liked, and then bought just custom doors. We did buy them from THD and as I recall the doors alone cost about $1500 or so. In the end it looked really nice.

• Use a local cabinet maker. Someone else commented this and I would highly recommend it. You would get better quality cabinets and most likely not pay much more.

• Here's my favorite but maybe not your cup of tea. This approach is probably more for r/DIY crowd (but I'm permabanned from there so I couldn't post it if I wanted to LOL). Craigslist. That's right - craigslist. I have found that cabinets are a dime a dozen on there. If you live near a really nice area check for listings there consistently. You would be amazed what "rich" people will tear out and dump on there so they can remodel to their heart's content. I'm building cabins for our equestrian bed&breakfast all the time. For my current one here are a couple of pictures of the cabinets I bought for $250 in CL.

I'll go further to say that if you look at the second picture that entire kitchen has cost me $1100 to build, including all appliances (another item always easy to find on CL), and a corian top (I bought a plain sheet off of CL and had to cut, rout, and glue it but that was a lot easier than I thought it would be thanks to Youtube). I had friends pay anywhere from $10-40k to remodel their kitchens and I feel like they need to have their heads examined. But to each his own.

Best of luck to you OP whatever route you go.