Regarding PSA pay: First year is $38.50 per hour with a 75 hour guarantee. ($34,650) Second year is $38.50 per hour with a 75 hour guarantee. Third year is $38.50 per hour with a 75 hour guarantee.

The sign on bonus (comes with a two year commitment) is $15,000. If you hold a CL-65 type rating you get an additional $5,000 sign on bonus. (CRJ type)

The second and third year you get $2,500 per quarter in bonuses. If you upgrade to captain, that bonus stops and you would get whatever retention bonuses are in place for captains (if any at that time)

So yes, 2nd year pay "could" be lower than first year pay as there are only $10,000 in bonuses vs the $15,000 for the first year. However, by the second year, you will be holding some kind of line and with SAP, you could easily be flying more than the 75 hours and making more money. Most will upgrade during or prior to their third year so third year pay will likely be higher than second year pay. If you don't upgrade and choose to not fly more, your third year pay will match the second year pay.
This salary is guaranteed base and does not include the hotel reimbursement allowance, per diem, etc.