the client has a brother hl-l5200dwt, but doesn't like that they have to choose what trays to print from by using the printer's onboard menu. they want to be able to choose trays through the office software when they go to print. amazingly, this is not possible with this printer! what are the choices out there for a b/w laser in the same price range as their hl-l5200dwt, please?
The ability to choose which tray the printer prints from is determined, not by the model of printer you are using, or by the application you are printing from, but by the (software) printer driver you have installed to use with your model of printer.
So the first thing that I would do would be to delete the setup that you have for your 5200 (in System Preferences --> Print and Scan). Choose Apple menu --> System Preferences --> Printers & Scanners --> select your printer in the list --> click the Remove button
Next download the latest version of the driver for the 5200 directly from Brother and install it:
http://support.brother.com/g/b/downloadtop.aspx?c=us&lang=en&prod=hll5200dw_us_eu_as
I strongly suspect that you will then have a choice of trays to print from.
I have a Brother laser printer sitting right here next to me, and even though it only has one tray, it still has a (greyed out) choice of trays to use in the Print dialog window. It may even be that you already have this choice and you haven't found it as it is a bit hidden:
Within the application you want to print from, go to:
File menu --> Print --> under Printer choose your printer model --> there is a drop down menu in the middle of this dialog box that normally has the name of the application you are printing from, click on it --> choose Print Settings --> Paper Source --> Tray 1 or Tray2 etc.
If none of that works, the next option is to go with a commercial printer driver that has expanded features and which supports your model of printer. I can suggest one or two if you like. But I very strongly suspect that this won't be necessary.