Cheap (cheaper than an RPI 1 B+) and accessible microcon+ Ethernet combo w/ DMA?

I'm looking for a microcontroller + Ethernet controller combination that would have DMA access. Reason for DMA access is that I'm targetting for about 50Mbps to 100Mbps (or something near this range) in terms of UDP throughput.

So far have tried DMA+SPI with an Arduino Due and W5500, but as expected it only reaches 15Mbps.

I was looking at the Taijiuino implementation with Ethernet through DMA, but it seemed there's no complete library for it yet.

Thanks in advance to any advice!

TM4C129 Connected LaunchPad
Or the MSP432 version:

RPi B+ is awfully cheap, though (~$30.)
OTOH, I don't think it will do 50+Mbps - doesn't its ethernet go through the USB hub?