Founder of multiple bootstrapped & profitable SaaS products. Specializing in React, React Native, Electron and Serverless (Node + Python) development
Obviously a technology fit is on a per-case basis, so it's good that you're asking questions first before just shoving a technology solution at a problem.
Couple things you want to consider when making a technology fit:
1) How difficult is it to find developers who are knowledgeable with the tech?
2) How expensive are these developers?
3) Are the features of the technology in line with the solution you're trying to build?
4) Are the caveats of the technology preventative of you completing the project?
5) How easy is it to leverage community solutions and not reinvent the wheel on common tasks?
6) How difficult is it to support and maintain the finished product?
7) How well maintained is the technology by the community?
Contrary to what you might think, Ruby actually started its life as a bash/console scripting language but was popularized by Rails. The idea of Rails from the beginning was to expedite all the little things that were consistently repetitive in project development.
The Rails community has done a great job of building out a community solution for almost every single problem I can think of. Most API integrations always include a Ruby/Rails integration right out of the gate.
Rails has gained enough momentum over the years that there's quite a large group of international developers as well as domestic, so finding someone to work on the project is pretty easy.
Hosting a Rails app is almost as painless as it can be, provided you keep the implementation pretty vanilla. Heroku offers free development tier project hosting, which includes Postgres DB support, so you can get started for almost no cost.
The common saying a few years ago was "Rails doesn't scale". This is true to some extent, and I really would consider a number of other platforms first before choosing Rails for things like chat messaging systems or highly-concurrent applications.
This doesn't seem to be your case, and your project looks pretty basic from a schema / interaction standpoint. I'd say Rails is probably a really good technology choice for the job, and it should help speed up development quite a bit.
Like every project, it "depends". Sorry, but that's the truth.
Here's how to make it cheaper:
1) Concentrate on one vertical, or thing you do well. This lets your shopping and checkout process be much more simplified. For Clarity, this is finding the right person to talk to, and putting two people on the phone together. If you try to do everything (calls, video, in-person meetings, local coffee connections, founder dating, etc) it'll be a nightmare to support all those workflows.
2) Try as hard as you can to stay away from being "local". Anything on the ground dramatically increases the pain in building out your marketplace. Clarity I love because there is no concept of cities, anyone can be anywhere. AirBNB has to onboard inventory in each city and have on the ground representation near where they have inventory.
3) Transparent, simple pricing. Clarity = Cost per minute * Number of Minutes. The second you try and get all fancy with your billables, people get confused and don't pay.
When selecting a technology, make sure you pick something where the cost to add features in (both time and $$$) is relatively simple. Additionally, avoid languages which require massive infrastructures (Java, .NET, etc).
I'd recommend Ruby/Rails or Python/Django. Both are incredibly fast at building out web projects. You may have success in Node but I've found it difficult when it comes to vanilla web applications.
If you stick to simplifying the project, the cost of maintenance will be minimal.