In terms of finding cheap or affordable ways to practice your French in Paris, Meetup.com has good options.

• For only 5 euros, I really liked the 1.5 hour intermediate-level group conversation class called Le New Frenchy.
• I also like the mixed-level 2-hour group classes with Christian Coffinet for 10 euros (the group is called French Conversationalists in Paris).
• For 12 euros (including a drink), Franglish was also an option (basically a speed-dating system, but for practicing languages), but I don’t know how often I would go considering you just end up having the same brief introductory conversation over and over again.
• I also went to the WICE French conversation group (free the first time, and then you pay per event or you can attend for free if you purchase a membership), which wasn’t for me, but would be ideal for someone around retirement age with a very high level of French.
• I also attended two free language pub quiz happy hours, one in French and one in Spanish (in case anyone would like to practice Spanish as well). These happy hours are monthly and hosted by the groups Happy Hour French and Happy Hour Spanish, respectively. These events were good for practicing and completely free.
• Polyglot Club has language exchange events about 4 nights per week, which are completely free (you are obligated to purchase at least 1 drink) and these events are good opportunities to practice languages and meet new people.
• There were other opportunities on Meetup.com, and although I didn’t get a chance to attend them, they might be worth checking out: Parler Parlor, Talk Time, and Café Conversation.

Couchsurfing.com also has a couple of opportunities to practice your French, like the Saturday afternoon East Side Cafe language exchange, and Conversation Table language exchange, both free of charge.

Tripmeeters.com also hosts events that, although they are more geared towards socializing, they are promoted as language exchanges and you really do get an opportunity to practice French if you make the effort (otherwise any French you meet would probably prefer to practice their English with you). Most events are free.

All of these events are ways to practice your French without having to shovel out the money for a formal course or private teacher, and they are also great ways to meet people in Paris (expats and locals).