Home altars are very important, in my opinion. They don’t only provide a focusing point for prayer, they provide a strong reminder to pray.
My first home altar cost me little to nothing as well. I found an old TV stand (TV stands work really well. They’re just about the right height, have a wide flat area on top, and generally an area for storage below). covered with handkercheifs to match the liturgical season, two candlesticks to match the season, hung a crucufix on the wall behind it, and put the Holy Family from my nativity set on there all year 'round. Over time I started keeping blessed salt, Holy Water, my rosaries and medals, and Holy Cards on it as well. I put a stereo undeneath for Gregorian Chant.
I just moved and decided to ‘upgrade’. I bought a new, larger TV stand, and now my cloths are seasonal colored with lace over the top (my sisters teased me unmercilessly about a guy buying lace, but hey, it’s on the Altars at Church and the hems of vestements) I have four candles instead of two, the two in the middle a little taller than the other. I purchased statues of the Sacred Hearts of Jesus, Mary as Our Lady of Graces, and St. Joseph and put them forefront. I also have a statue of St. Padre Pio that is much smaller than the others, and even smaller than that is a little pewter Holy Family that holds a 1 Decade rosary that my sister’s fiance got for me at Mission San Diego. I have a little wooden chest that holds my Blessed Salt, and the bottle of my Holy Water, my Family Bible and my book “Christian Prayer”, and the back has a row of Holy Cards. I recently ordered an incense burner, but if I might get a different one.
To the poster just before me, no, a Home Altar isn’t used to celebrate the Holy Sacrifice of the Mass, it’s used to foster a prayer life. A better term would be Home Shrine, but the phrase Home Altar is so ingrained into Catholic Culture that I doubt it’ll change now.
also, this page has some good information on Home Altars.