Hey guys. So I took the new SAT in June and received a 1450/1600, which is a nice jump from my last SAT score (1800s/2400) but now I am wondering if I should take the ACT. I made a mistake in only focusing on the SAT, so I will need to study extra hard for ACT. But here are some things that I need to consider. I am taking 4 AP classes this year including AP Literature and I have college applications this year. Of course in order to seem competitive to some highly selective schools such as an Ivy League I understand that I may need to bump up my SAT scores. However, i am also planning to take the SAT II. Sadly, I am unable to pay for taking the New SAT due to financial problems (since i can only have 2 fee waivers). So my only affordable option is to take the ACT and get a fee waiver from that. Of course I know that my decision is mine alone, but I want to see what you guys think about this decision. Thanks for reading! 
Your 1450 is a strong score, no doubt about that. But IMO, it might not be worth it to take the ACT- you are going to be very busy with college apps and your 4 APs, and taking the ACT would only be worth it if you significantly improved your score (at least a 32 to be equivalent with the 1450/1600). So, I caution against taking it and instead focusing on your schoolwork, apps, and the SAT IIs.
My S only did PSAT/SAT prep. He did review a practice ACT just to get a feel for the structure and timing. He got around your high SAT score for his PSAT then got a 34 on the ACT. Some people just click better with one test or the other.
Try a practice ACT. If your score is competitive with your SAT then try the ACT once, especially if you can get a fee waiver for it. Don’t invest a ton of time in studying for it if you don’t have the time. Review the format and timing. Your 1450 is good, but it wouldn’t hurt to see what you could do on the ACT.