Flower bed build up.... DIY or hire someone?

I have two long flowerbeds that line the outer perimeter of my back yard. They are lined with mature crepe myrtles (25' high or so, about 13 of them total) that shade most of the yard. I have raised the canopy by pruning considerably over the past couple of weeks. Anyway, last spring I took a stab at dressing up the beds - hand tilled, laid compost, topsoil, and mulch - then planted calladiums, hostas, and holly ferns. I also edged the beds with Liriope, mostly seedlings, but some more mature plants. Either from too much shade, competition with the crepe myrtles, or neglect, pretty much everything (aside from the Liriope) died by the end of the summer.

Back to the question at hand. I am looking to raise the beds, as I know at least one is too even with the natural soil level. I got a quote from a landscaping company that itemized the job as following:

Soil(4 cubic yards)
$170 for materials, $390 for installation
Micro Irrigation
$250 for materials $60 for installation

They also quoted some planting and mulching, but I know I can do that myself.

Am I getting hosed? Is this something that I should try and tackle myself? I've never constructed a berm/raised type bed.

Sorry for the long post. Any suggestions or advice would be greatly appreciated.