Btw does purchasing a property still bugged in this version ?
Not aware of any bugs.
School lessons cost 2$ to 5$ from F- to C- and won't be refused (though performance might be lacking). F-/D- tutor lessons cost 5$ too.
The guild pays a speed bonus of 10$ per day. So if you can spend less than 10$ per day to save a day of training, it's worth it.
You just need enough reserve to pay the bills until you can complete the contract: budget 20$ to 30$ per decade depending on food costs.
Assume it will take 40 days to reach D- (it shouldn't take that long). That's 4 x 30$ = 120$ (it shouldn't cost that much).
So from 260$ you have a reserve of 120$ and a budget of 140$ for training.
Starting from F- for 2 common skills, a single 2$ school lesson each gets you to D-.
Then suppose it takes 4 school lessons to C- and 8 more to B+. That's 2$ + 4 x 2$ and 8 x 5$ = 52$ per skill.
So you have 36$ for discretionary expenses (clothes, drugs, tutor, spa, etc). If you can complete training in less than 4 decades, or reduce food costs, you can free up more sparks. If you run out, you can take out a loan at the cost of 100$, equivalent to missing out on one decade's bonus.
Example:
I started a new game on Extreme difficulty with 200$ and no points invested. Took first guild contract offered: 60$ prepayment for D- assistant. Slave provided was Mature, Plain, Healthy, Insensitive, Reserved, Intelligent, Willful, Open, Voluptuous. No skills. Gave her school uniform and slippers.
On day 16, with 120$ remaining, she is Slender, B+ Athlete, B+ Secretary and B+ Elocutionist and is willing to do housework. All other skills still F-. Did not go to the arena, so no extra income. Only used verbal punishments (now ineffective due to repetition without follow-through), free time rewards and a couple of spa visits to raise her mood. All lessons from school and tutors. She is still F- until she gains more obedience but there is plenty of time. Master is Frail, has only eaten canned food and drank kamra for extra energy. Now that the slave is acting as maid, the master can regenerate more energy than he spends cooking and cleaning.