Is $26,000 to waterproof exterior basement foundation walls without insulation a fair price?

I'm looking to see if I can DIY waterproof and insulate my exterior basement foundation walls and if it is actually needed or will make a difference and how much time this job will take. I got a quote of a company to do it for $26,000 with no insulation but that's way more than I want to spend so I'm considering DIY. The mortar is deteriorating between blocks and likely letting ants find their way in our basement, and obviously moisture gets in during the summer. I added good gutters and 10' extensions to get water away from the house. We have sandy soil with good drainage and no high groundwater issues; our basement has never flooded naturally. Last year, I accidentally left a soaker hose on, and it burst overnight, gushing water along our foundation wall all night, which found its way into the basement through the gaps in the mortar. I don't have a sump pump nor a need for one, but it would have prevented that freak random flood. The water table is about 20' below grade. Other than that, the basement has always been dry in the nearly 6 years that we have lived here. My basement doesn't really have ongoing water infiltration issues through the walls, but the only reason I'm considering doing this work is to repair the crumbling mortar joints, to seal the wall to lower the humidity level in my basement, and to insulate the wall against winter cold. I'm also wondering if the contractor insulated the wall over the top of the waterproofing membrane or put in a French drain. I don’t have a sump, but maybe I’ll have to install an outside sump and put a pump in it or something and run the French drain line to that.