I think you could do a lot with a different color scheme on the exterior wood siding and trim. You might try a local painting company that can help you select some color options. Also, I think you could have a landscape company look at your current planting and make some design recommendations. It would help to tie in some landscaping on the left side of the driveway and have it coordinate in some way with the landscaping on the right side of the driveway. It looks like you may need to remove some concrete to accomplish this. That tall scrub in the middle is to big and obscures the entry.

http://houzz.com/photos/1068748
This is a nice dark wood that could modernize the home and appears to be a similar style.

Sorry, noticed you are on a budget but a similar color could work with a complimentary trim
http://houzz.com/photos/124888

The shed roof entry is the one thing you might price altering. If you don't need the shade provided, maybe it could be switched out for an open wood grid-type. Even if still in the shed shape, it wouldn't look quite so blocky. Is there an opportunity to have flowering vines wind around the brick columns at the front? Then maybe grow over the open grid roof if you changed it? Trimming or removing the tall shrubs by the entry area would also open it up. Then you could put a new version of house numbers centered on the horizontal beam, and they would be visible. A new neutral, less contrasting body/trim color scheme would help as well.