Honestly I don't see any real problem here with paying 100 simoleons. I assume you're placing these food stalls because you want to learn the recipes, supplied by the various stalls ?
I am capped out on 9,999,999 simoleons, no cheats no mods. Earning money is the easiest part of this game.
If I may offer suggestions to the struggling poor people ? - Don't have kids right away, they will consume a lot of your time ( assuming you're trying to raise them right :P ).
1 - Try starting out as a creative type ( Creative, Perfectionist ) doing paintings and work on purely Abstract when you finally unlock them. I suggest joining the Painting career and work towards picking up the Marketable and Creative Visionary Traits as soon as possible.
2 - Visit the spice festival and harvest the dragon fruit, plant as many as you can and harvest / plant / sell the fruit to your hearts desire.
3 - IF.. you want to work on your Baking and IF ... you have the expansions / packs for the Ground floor Entrepreneurs Table or the Come and get it street store - sell here at a 300% mark up
Also these Tables allow you to sell any Food you make. The highest selling food I found was the Lava Bundt Cake ( Baking lvl 10). To sell your food, firstly " pick up serving " until all serves are seperately stored in your inventory then place them all into the Table's inventory. the Lava cakes were selling for me between 2.9k - 3.4k simoleons per serving.
Once you have enough revenue coming in complete the Fabulously Wealthly Aspiration.
This will allow you to earn simo's based on your standing cash every week... it will grow and grow until you are earning hundreds of thousands of simo's every week
I hope this washes away any money troubles you ever have again.
Gluck.