For TLDR, read the last paragraph.

Years ago I had a generous coworker give me a brand new rain suit he had ordered for himself and then changed his mind. I think it's the Columbia HydroTech, but the label doesn't say for sure. In any case, it's served me well for years. Unfortunately, it's starting to leak. I wore it for a long walk a week or 2 ago, and found there were damp spots in my jacket and pants under the rain suit. I assume the leaks are at seams. It is fully taped on the inside, but I've just now taken a close look at it and noticed the edges of the tape peeling in a few places.

Before this jacket was given to me, I had been considering making my own. I really wanted to try working with silpoly PU4000 fabric. It's really tough to convince the boss to spend money on anything we don't absolutely need, but the cost of all the materials would probably be less than $40, definitely less than $50, so I could probably swing it. The bigger problem is the investment in time. I simply don't have enough hours in the day for something like this, so it would mean sacrificing sleep and doing the project over many days or weeks. Nevertheless, that option had always been in my mind, even after I got the Columbia suit, simply because the DIY suit would probably be lighter and the project would be fun.

Another option that has always been in the back of my mind is the extremely light and low priced Ultra-Lite suits from Frogg Toggs. The only down side to them I know of is their durability. But for < $20 for a complete suit, that doesn't seem like that big of a deal. I'd just have to carry a way to tape up rips in the field. Reportedly, Tyvek tape works well for this. I see they've released a new version now, the Ultra-Lite2.

So I have 3 options, try to re-tape the Columbia suit, buy a Frogg Toggs suit, or make my own rain suit from scratch. What is your opinion on which way to go with this?

A 4th option would be moving to Arizona cause it hasn’t rained here for near a year it seems. They say maybe next week but they say that a lot. I just carry a pullover Patagonia Houdini that turns back the rain well. Mostly it’s used as a windbreaker.
But if you really want to make your own then why not just do it. That might be a satisfying challenge. Less than $20 for a light Frog Togg suit does sound okay to me too. I guess you just have to choose for yourself.

I've had good luck making rain pants using Green Pepper pattern F578, which is now #128. I leave out the leg zippers to save a little weight. They also have a rain suit pattern that may include the same pants (#134).

https://www.thegreenpepper.com/wp-content/uploads/2013/11/128-web.pdf

The pants are easy. The jacket would be more difficult and time consuming.

I haven't used them, but the Frog Toggs Extremelite series looks better than the original Frog Toggs in both fit and durability. I've seen them in a store, and they seem better, at least. A little more expensive, but still much cheaper than most.

I gave up trying to re-seal an old Marmot rain jacket, but it was pretty far gone, with the w/b coating peeling off. Small sections of the seam tape could be repaired with Seam Grip, if the rest of it is still adhering well.

Repairing worn out rain gear seems like an exercise in futility to me. Repair one hole; wear it out in the rain to find 5 more. Hopefully it is only the seams that are leaking, but who knows? You would probably need to remove the old tape too which could further damage the garment and surrounding waterproofness. To me it is a task for someone who just can't emotionally give up on a garment.

If you are too busy to make the pants, I would buy the Frogg Toggs and see how they work out for your intended use. With rain gear the stuff just tends to wear out. I don't buy for the long term. I buy expecting to replace it in a few years.

I've made up my mind. I'm going to go for the Frogg Toggs Ultra-Lite2. At $20, it's hard to say no.

Thanks for everyone's input!