I have found plenty of icons online, but have yet to find images for other types of controls except 1-off examples. For example - buttons, tabs, dropdown menus, sliders, table headers, panel headers, etc. I've found plenty of tutorials, but our attempts always look bad in comparison (particularly for buttons and tabs).
Are there any free or inexpensive libraries that include this type of thing? We found some asp.net control libraries that look nice, but paying hundreds just to utilize the images seems like a waste (we are using php and asp.net mvc, so the server controls are worthless for us).