There are lots of PIM tools out there. The affordable bit is the harder since that is so relative.
Here Pimcore is the fastest growing open source PIM/DAM. It’s completely open source, so no upsell later when you want more modules. It also includes a CMS if needed. Pimcore is great from startups all the way to enterprises. Companies like Gogo Air, Smuckers, Ikea and Milwaukee Tool use it.
At Plytix we offer an out-of-the-box Product Information Management system designed for small to medium sized companies. We offer a free version to help people get their product data in order. Our big mission is to make the tool easy to implement and use, but also scalable for companies that may not have the budget to drop thousands while they grow into it.
There are other affordable options on the market like Akeneo & Pimcore that are open source, though they generally require a lot of time and effort to implement or even costing consulting hours. The other cheaper PIM systems out there are companies such as Saleslayer and SkyPIM.
Like Ishan said one of the best Product Information Management tools is Pimcore.
Advantage of Pimcore is that it is a fully open-source, it has fully integrated platform for Product Information Management, Digital Asset Management, Enterprise Content Management and it can be easily integrated with other applications.
Pimcore can be a little hard to learn for beginners, but don't worry Pimcore has strong partner network and community support.
If you are struggling where to begin , I recommend starting here