I'm one of those who can't leave anything alone... I brewed exactly one extract kit to the recipe specifications. The next couple kits, I modified. Then I broke out on my own into doing BIAB partial mashes. The problem was, my brew days got quite long and after fighting it awhile, I kind of burnt out. Too busy with other things and I didn't look forward to spending an entire day brewing, especially with my hip problems (auto accident).
Now for Christmas, my brother got me a good outdoor burner. So I invested in a new 15 gallon kettle (stainless with a bulkhead fitting, Spike Brewing), copper counterflow chiller and the mash tun setup. I didn't need to go all out like that, but it's where I've wanted to take my hobby for awhile. As far as scales and whatnot goes, I had all of that from doing partial mashes on the stove. I had bought a postal scale for weighing grains (ebay, IIRC it was around $35), and I was given a kitchen scale (IIRC, walmart around $30). The kitchen scale is a little more precise so I use it for measuring hops.
I ended up buying two coolers, a 72 quart Coleman Extreme from walmart and a 48 quart rubbermaid from Home Depot. Picked up some fittings from a local plumbing supply and put together a mash tun (using Denny's Cheap and Easy build as a guideline) and put together what I refer to as a Hot Water Tank (HWT). By having the second cooler, I can heat my mash and sparge water using only one kettle. At first I had thought about using my old kettle for heating sparge water but when I discovered that some of my grain bills for doing 11 gallon batches will take 7 gallons of water, well, that doesn't fit in a 5 gallon kettle very well, kinda wants to spill over all the time instead of staying where it belongs...
Right now I'm working on getting up a couple videos on putting together the coolers. Not sure when I'll have it up, but I'll try to remember to mention it. I will say though, the extra investment in equipment has paid off. My last brew day I did an 11 gallon batch in 5 and 1/2 hours, and that included measuring all the ingredients, putting the mash tun together and rigging up the HWT. If I prep the night before and don't have to work on equipment, I should be able to cut at least an hour out of my brew day. And at the end, I had nothing to clean up, I cleaned as I went. A considerable change from my 8-9 hour brew days plus clean-up!