Retainform sells dental retainers it expects sales of $15,000$ units in quarter $1$ and a $6\%$ decrease each subsequent quarter for the next $3$ quarters. The company will sell retainers at $$100$ per unit during the first quarter and then it expects that the sales price will decrease by $10\%$ each quarter for the next $3$ quarters prepare a sales budget by quarter for the first $3$ quarters