It wasn't free he purchased it with OASIS credits.
In the film the OASIS economy isn't really referenced at all, however, throughout the book you see different monetisation models used by Gregarious Simulation Systems aka Gregarious Games in the movie.
These include:
* the OASIS pubic school system (which make up a big part of "Level 1 in the book)
* in Level 1 0005 we learn that
Any business that wanted to setup shop inside the OASIS had to rent or purchase virtual real estate (which <PERSON> dubbed "surreal estate") from GSS.
* and in the next paragraph we learn about virtual items…
In addition to the billions of dollars that GSS raked in selling land that didn't exist, they made a killing selling virtual objects and vehicles. The OASIS became such an integral part of people's day-to-day social lives that users were more than willing to shell out real money to buy accessories for their avatars: clothing, furniture, houses, flying cars, magic swords and machine guns. These items nothing but ones and zeroes stored on the OASIS servers, but they were also status symbols. 130
Most items only cost a few credits, but since they cost nothing for GSS to manufacture, it was all profit.
Interesting parallel with the massive earning seen in the real world with the free to play game Fortnight reporting revenue of $126 million in February sales of virtual items
* The book goes on to mention that OASIS becomes a synonym for "internet" and you can start to extrapolate how much of the worlds economy would be running through OASIS by looking at the world economy today
In the book OASIS virtual credits are interchangeable with real-world currency although there is not discussion about exchange rates and given the books was written prior to the rise of blockchain currencies like Bitcoin ~ it's reasonable that it's presented as a fait accompli.
Also I don't recall that he got the suit specifically from GSS, in the books there are multiple manufacturers and the first full immersion system he acquires is through a marketing deal. In fact the offers start rolling in once he gets the first key.
From Level 1 0013
I'd also received several endorsement-deal offers from companies who wanted to use Parzival's name and face to sell their services and products. An electronics retailer was interested in using my avatar to promote their line of OASIS immersion hardware so they could sell. "Parzival-approved" optic rigs, gloves and visors.
In fact he received lots of offers for everything from toys to pizza companies. 130